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Finding the Fourth Proportional to 398.21, 549.45 and 258.35

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Solution

The fourth proportional to 398.21, 549.45 and 258.35 is: 356.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.21 : 549.45 = 258.35 : x
  2. Step 2: Convert to fraction form
    398.21/549.45 = 258.35/x
  3. Step 3: Cross multiply
    398.21x = 549.45 × 258.35
  4. Step 4: Simplify right side
    398.21x = 141,947.66
  5. Step 5: Solve for x
    x = 141,947.66/398.21
  6. Step 6: Final answer
    x = 356.47

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.